Micromachined V-groove chips are commonly used in the optical fiber industry and photonics industry to align and position optical fibers. Typically, V-groove fiber arrays are made by placing optical fibers in V-grooves of a V-groove chip, placing a lid on the fibers, and then securing the assembly with adhesive. The lid can be a V-groove chip or a flat silicon or glass plate. The adhesive is typically a UV-curable or heat-curable epoxy.
The optical fibers must be carefully located in the V-grooves during manufacture of the array. Specifically, the optical fibers must be disposed in contact with the surfaces of the V-grooves. Also, for fiber arrays having polarization-maintaining fiber, the optical fibers must have an accurate rotational alignment. Also, some fiber arrays need to have optical fibers placed so that the fiber endfaces are fixed at different longitudinal positions.
It can be difficult to position optical fibers in conventional V-groove chips. This is because adhesive used to secure the fibers wicks by capillary action into the small spaces between the fibers and V-grooves. Since the adhesive wicks into these spaces, the entire length of the fiber is secured to the V-groove chip in a single step. It is not possible to secure the fiber in the V-groove in multiple gluing steps. This is a problem for certain fiber arrays because multiple gluing steps can improve the alignment of optical fibers.
U.S. Pat. No. 5,257,332 to Pimpinella discloses a fiber coupler having v-groove chips.
U.S. Pat. No. 5,748,822 to Miura et al. discloses a module for connecting an optical fiber to an optical element such as a laser diode. The module has a vertical groove cut perpendicular to the V-grooves. The vertical groove is positioned to abut the fiber endface and provide longitudinal positioning of the optical fiber.